Research fish wheels used for salmon mark and capture study

The Native Village of Eyak’s Chinook Escapement Monitoring Program began in 2001, with a feasibility study to determine if fish wheels could be used for mark/re-capture study on the lower Copper River

Biologists and fisheries technicians with the Native Village of Eyak’s Department of Environment and Natural Resources (NVE-DENR) have had a productive summer season monitoring Chinook on the lower Copper River this year.

NVE’s fisheries personnel are performing high quality research and gathering the necessary data at their field camps to ensure that the Eyak People can subsist on local fish populations for generations to come, according to NVE’s DENR Coordinator and Fish Biologist Matt Piche.

“Significant data gaps exist for Alaska’s fish populations,” said Piche, “Including the local fish stocks that the Eyak have thrived upon since time immemorial.”

The Native Village of Eyak’s Chinook Escapement Monitoring Program, (CEM) began in 2001, with a feasibility study to determine if fish wheels could be used for a mark/re-capture study to determine the amount of Chinook salmon present in the lower Copper River.

By determining how many fish are in the river, the annual escapement – the number of fish reaching the spawning grounds, can be calculated and provide a tool which monitors the health of the Copper River Chinook salmon population from year to year, he said.

Piche explained that Chinook and Sockeye salmon have similar run timings on the lower Copper River, beginning in early May and ending in late July.  He said the fish are mixed as they migrate to their natal stream.

“In order for us to conduct a mark re-capture study,” Piche said, “We need to effectively sample a portion of the salmon run. We use large, research fish wheels to capture salmon. By fishing the wheels in or near major channel constrictions on this otherwise highly braided river, we are able to increase our catch rate because the higher velocity water flowing through tends to be avoided by most salmon.”

Because of this, he said, the salmon swim through the eddies and near river banks where the current is less. This allows the salmon to conserve energy for their spawning migration. Piche said this where NVE places their fish wheels.

A fish wheel is a device for catching fish which operates much as a water-powered mill wheel.

A wheel, complete with baskets and paddles, is situated on the river, usually upon a floating dock. The wheel rotates due to the current of the stream pressing the bottom basket or paddle that has swung down into the water. The baskets on the wheel, swinging downstream only at the speed of the current or more slowly, capture fish actively swimming upstream and also can capture fish simply drifting.

NVE has two remote Copper River camp stations assigned to the CEM project. A mark re-capture study must have two study sites, Piche said.

Baird Canyon Camp is located on the Copper River at kilometer 66 and Canyon Creek Camp is located at kilometer 152 on the Copper. Baird Camp is NVE’s marking or tagging site and Canyon Creek is their re-capture site.

A third feasibility study site existed from 2012-2015 on the Gulkana River (a tributary of the Copper River). This site, Piche said, is 230 kilometers from the mouth of the Copper River. The study at this third site concluded in 2015.

“Each camp has two fish wheels,” Piche said. “The fish wheels capture both Sockeye and Chinook salmon and deposit them in two large, live-tanks on each fish wheel. Each live tank has two escape panels that allow many of the smaller Sockeye salmon to escape, while retaining all Chinook salmon measuring at a length greater than 450 mm mid-eye to fork (MEF).”

Several times a day the crews at the camps boat to the fish wheels and sample the fish in the live tanks. All bycatch (non-Chinook salmon), are released, Piche said.

“The Chinook salmon captured at Baird Canyon are tagged with a primary mark (TBA-PIT-TAG),” Piche said, “Then given a secondary mark (an operculum hole punch on the right side), measured mid-eye to fork, and some are sampled for genetics, age and sex, and then released to continue their spawning migration.”

Fish captured at Canyon Creek camp, which is upriver from Baird Canyon, are sampled the same way, he said, except that instead of applying tags, the NVE fisheries folks are looking for tagged Chinook salmon.

“All Chinook captured at Canyon Creek camp,” Piche said, “Are given an operculum hole punch on the left side, measured and some are sampled for genetics, age and sex, then released to continue their migration upstream.”

The project allows NVE to get a ratio of tagged vs. untagged fish at their upriver Canyon Creek camp and then apply the same ratio to the amount of fish tagged at the lower river Baird Camp.

“This ratio provides an estimate of how many salmon migrated past Baird Canyon,” Piche said, “That weren’t captured by our fish wheels, providing an estimate of total abundance through Baird Canyon.”

The scenery is beautiful, raw and rugged on the lower Copper River where the camps are located.

Four people, all NVE employees, live at the camps – a camp leader and three seasonal fisheries technicians populate the camps during the Chinook migration.

“Baird camp is led by Jimmy Paley and Canyon Creek Camp is led by Jonathan Shurtz,” Piche said.

Piche is the CEM project’s principal investigator. John Whissel is NVE’s director of the DENR program.

“John Whissel, Ivy Patton and several interns offer critical logistical support,” Piche said, “Throughout the season, both in the office and in the field.”

The CEM program is funded solely by the U.S. Fish and Wildlife Service’s Office of Subsistence Management Fisheries Resource Monitoring Program (FRMP). The fulltime project principal investigator position and the intern positions are funded through the U.S. Fish and Wildlife Service’s Office of Subsistence Management Partner’s for Fisheries Monitoring Program (PFMP).

“By 2003, NVE was able to produce a defensible and accurate estimate,” Piche said, “On the number of Chinook salmon migrating past Baird Canyon on the Copper River, 66 kilometers upstream from the river mouth. NVE has produced this abundance estimate every year since 2003. This abundance estimate represents all of the Chinook salmon migrating past the commercial fisheries, into the Copper River, and through Baird Canyon.”

According to Piche, the escapement is calculated in the following manner: NVE obtains the lower river Chinook salmon abundance (through NVE’s fish wheel mark re-capture study); the Alaska Dept. of Fish and Game calculates the in-river harvest estimate for Chinook salmon that year based on mandatory reporting requirements for personal use, subsistence users and sport fish guides, as well as annual mail-out sport fish surveys; the in-river harvest estimate is subtracted from NVE’s lower river abundance estimate, which provides the system-wide escapement estimate for Copper River Chinook salmon.

“This occurs annually,” Piche said. “Additionally, the Alaska Dept. of Fish and Game requires all commercial fishermen to report their catch, as well as subsistence users who fish out on the flats; therefore, total run size – the number of fish returning to the Copper River Mouth each year, can be calculated by taking the harvest estimate occurring on the flats, commercial and subsistence, and adding it to NVE’s lower river abundance estimate.”

The Native Village of Eyak has been involved in fisheries resource management projects since 2000. NVE Environmental and Natural Resource collaborations and partnerships have taken place with the following organizations: Ahtna, Inc.; the Chugach Corporation; the Eyak Corporation; Ahtna Tene’ Nene; the C&T Committee; Alaska Department of Environmental Conservation and Environmental Protection; the Alaska Department of Fish and Game; the Bureau of Land Management; the City of Cordova; Copper River Inter-Tribal Resource Commission; Copper River-Prince William Sound Native Fishermen’s Association; the Copper River Watershed Project; Ecotrust; the Environmental Protection Agency (Region X); Minerals Management Service; Nunagpet/CEPC; the Prince William Sound Science Center; the University of Oregon; the U.S. Environmental Protection Agency – Indian General Assistance Program; the U.S. Fish and Wildlife Service – FRMP; the U.S. Fish and Wildlife Service – PFMP; and the U.S. Forest Service –Cordova Ranger District.

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Cinthia Gibbens-Stimson is a staff writer and photographer for The Cordova Times. She has been writing in one form or another for 30-plus years and has had a longstanding relationship with The Cordova Times starting in 1989. She's been an Alaskan since 1976 and first moved to Cordova in 1978. She's lived in various West Texas towns; in Denver, Colorado; in McGrath, Cordova, Galena, Kodiak, Wasilla, Anchorage and Fairbanks, Alaska and in Bangalore, India. She has two children and three grandchildren. She can be reached at cgibbens-stimson@thecordovatimes.com or follow her on Instagram @alaskatoindia.